Dental chair



SSheets- Sheet 1. D. STUCK.

DENTAL CHAIR.

(No Model.)

N0. 491,611. Patented Feb. 14, 1893.

INVENTOR 5 Sheets-Sheet 2.

(No Model.)

D. STUGK.

DENTAL CHAIR.

Patented Feb. 14, 1893.

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(No Model.) 5 Sheets-Sheet 3.

D. STUCK.

DENTAL 01mm.

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(No Model.) 5 Sheets-Sheet 4.

D. STUCK.

DENTAL CHAIR.

No. 491,611. Patented Feb. 14, 1893.

INVENTOR aag.

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5 Sheets-Sheet 5.

DSTUGK.

DENTAL CHAIR.

(No Model.)

No. 491,611. Patented Feb. 14, 1893.

INVENTOR I S E S S M n W w noims PETERS co. Puo'raufuo, msmncrm, u c,

UNITED STATES ATENT OFFICE.

DEWELL STUCK, OF ROCHESTER, NEW YORK.

DENTAL CHAlR.

SPECIFICATION forming part of Letters Patent No. 491,611, dated February14, 1893.

Application filecl March 19, 1892- Serial No. 425,548. (No model.)

To ctZZ whom, it may concern.-

Be it known that I, DEWELL STUCK, a resident of Rochester, in the countyof Monroe and State of New York, have invented certain new and usefulImprovements in Dental Chairs; and I do herebydeclare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it pertains to make and usethe same.

The invention relates to dental chairs and has for its object toincrease the ease, certainty and range of adjustment of various parts;and it consists in the construction hereinafter described andparticularly pointed out.

In the accompanying drawings: Figure 1 is a side elevation of the chair;Fig. 2 is a partial central vertical section; Fig. 3 is a partialsection on line 33 of Fig. 4; Fig. 4 is a plan of the seat frame andlocking mechanism; Fig. 5 is a vertical central section of the head restsupport; Fig. 6 is a section on line 66 of Fig.5; Fig.7 is a section online 7-7 of same figure; Fig. 8 is a section on line S8 of Fig. 6; Fig.9 is a section on line 9-9 of Fig. 2; Fig. 10 is a section on line l010of Fig. 1; Fig. 11 is a section on line 11-11 of same figure; Fig. 12 isa plan of the main foot rest; and Fig.13 is a plan of a supplementaryfoot rest. Fig. 14 is a section on line 14-14 of Fig. l; and Fig. 15 isa plan of the part of the seat frame upon which the arm rest issupported.

Numeral 1 denotes the base or floor plate and 2 the standard of thechair. This standard preferably in horizontal section is closed at thebottom. It has an open front and top and is rearwardly extended at itsupper part the whole being arranged and constructed to adapt it toreceive elevating mechanism to be hereinafter described. 3 denotes asupporting rib formed on the base and upon which the standard rests.

4 indicates a plug having a flanged head fitted or seated in the base asrepresented and provided with an angular body 5 passing through thebottom of the standard 2, and with a screw threaded portion 4'.

6 is a clamping nut engaging said screw to which nut is secured byfastening screws a lever 7. The standard can be clamped to the base bysuitably turning the nut down upon the screw.

ets 13 fixed on the reservoir.

8 denotes a fluid reservoir, 9 a pump of which 10 is the piston and 11the piston lever. This has a fulcrum 12 in thestuds or brack- Under itsinner or short arm is a spring adapted to draw it down after it has beenraised by the forcing down of the lever arm. This lever is looselyconnected with the piston by a rod or bar 14 having pivots 15.

16 denotes the piston cylinder and 17 is an opening in the top of thereservoir to permit fluid overflow to return to the reservoir. The inletand check valves are respectively denoted by 18 and 19 and their closingsprings by 20 and 21. Removable plugs are indicated by 22.

23 is the main cylinder and 24 its piston loosely connected by asupporting rod 24 with lever 25 and by the medium of link 26 with lever27, said levers having fulcrums supported in the standard at 28 and 29respectively.

30 is a valve having its seat in the diaphragm 31. Its stem has a screwthread con nection with plug 32.

33 is a valve operating handle and 34a handle retaining nut.

To elevate the seat support the pump is operated in a well known mannerthe valve 30 being securely closed. Liquid such as oil, glycerine or thelike is drawn from the reservoir and forced under piston 24. The pumpingbeing suspended when the seat has been raised to the desired height thevalve 19 is automatically closed by its spring and the seat is held at afixed elevation. To lower the seat the valve 30 is opened and the liquidpermitted to flow from cylinder 23 into the surrounding reservoir.

The chair seat frame denoted by 35 is supported upon the standard andupon piston 24 by means of the pivoted rod 24 and the two wide levers 25and 27 having fulcrums 28 and 29 in the standard and pivotally conalarge range of vertical adjustment is secured. The seat is locked in anydesired position with reference to a horizontal plane by means of thepawl 42 adapted to engage a rack 43 situated near the junction of theseat and foot rest frames. The pawl has a fulcrum 44 in the seatelevating bar and a treadle arm 45.

46 is a spring normally holding said pawl in engagement with the rack.

A foot rest platform is denoted by 47 and a foot rest roll frame by 48.This frame has in each of its end walls a slot 49 having a notch orpocket 50. Lugs adapted to fit and be moved in said grooves are denotedby 51, and foot rests or foot rest rolls by 52. This frame and therest-s are adapted to be ad justed by sliding upon the lugs and they arelocked in their extreme position by the lugs dropping into the notches50. A similar rest for children is indicated by 53 the foot restplatform support being cut away at 54 to receive the supporting arms ofsaid foot rest when it is pushed inwardly as indicated by dotted lines.

The head rest 55 shown in Fig. 5 is supported from the seat frame 35 bypivots 57 connecting the brackets 58 of said frame with the legs 59 of aswinging back frame 56 U shaped in cross section as shown.

60 is a brace or supporting bar pivoted to the seat frame and adapted tobe clamped to the back frame by means of a screw 61 and a nut 62havingahandle 63. The back frame is made vertically movable on the screw61 and brace 60 by means of the slots 64 and 65 in the frame.

66 denotesaslideor innerback frame similar in cross section to the mainor outer frame 56. It is provided with ribs 67 adapted to run in groovesin the said back frame. It is held at any desired elevation by the setscrews 68.

69 is a sliding bar the edges of which fit and are adapted to move ingrooves 70 formed in the slide 66. 71 is a rod vertically movable in apassage in said bar. 72 denotes a friction pawl pivoted in aslot in thebar 69. One end extends intoa recess in the rod 71 and the other isadapted to bear on the interior of the slide 66. The bar 69 passesthrough an opening in the end of a lever 73 having a fulcrum at 74within alever 75 having the form of a shield or cover. The slide 69 alsoextends toward or into an opening in said shield which opening iscovered by the head 76 of the rod 71.

Wis a nut provided with a handle and fitted to the rounded screwthreaded upper end of bar 69. The screwing of nut 77 against lever 73moves said lever about its fulcrum and tends to depress its opposite orright hand end, which through the action of the bolt 79 pulls down theleft hand end of leveror cover 80 and raises its opposite end with theeffect to clamp the head rest. If the nut 77 be farther screwed up itwill produce a relative downward movement in the bar 69 whereby the heelof pawl 7 2 is thrust against the bottom of the recess in rod 71 withthe effect to throw its toe outward against the slide bar 66 and bindthe bars together. Though these movements are for the sake of clearnessdescribed as successive and as pertaining only to levers 73 and 80 andbar 69 they are practically simultaneous and the effect would be thesame if in operation the levers 75 and 81 and rod 71 were moved to aslight extent in tion nor that it have an extension of the form shown toreceive the fulcrums of the elevating levers, nor that said levers beconnected by a link near the pointof attachment of the piston rod. It isimportant that the levers be so arranged and connected that they willvgive to the seat a large range of movement in a vertical line and inrespect to the head restit is considered material that the same deviceserves to raise the adjustable slide bar, lock the same and clamp thehead rest in position.

In Figs. 1 and 14 is represented a detachable and reversible arm rest82, provided with an extension or foot 83 fitting a socket in the seatframe. 84 is a pin also entering one or the other of the sockets 85 inthe frame which pin holds the arm rest-from turning about the extension83. The post of the arm rest is bentlaterally as indicated in Fig. 14,the effect being to widen or narrow the seating space according to theadjustment to suit different persons, or in particular emergencies topermit the operator to get nearer to the patient, the rest beinginwardly inclined at such time.

I am aware that chair standards locked to a base by a spring pinengaging a notch or hole, and a system of parallel levers adapted toelevate a bracket stand and to be locked in various horizontal positionsby a rack and pawl, and seat elevating pump cylinders with suitablevalves and overflow receptacle, and adjustable foot roll frames are notnew. My improvements relating to dental chairs are specificallyhereinafter pointed out.

Having thus described my invention what I claim is:

1. The combination of the standard, the parallel levers having fulcrumstherein, the seat frame, the bar 39 pivoted to each of said levers andextending backwardly and overthe point of application of power to saidlevers and journaled in said frame, and mechanism for moving the leversconnected to the same at one ICO side of said fulcrums and immediatelyunder the connection of bar 39 with the seat frame, consisting of apiston having a rod pivotally connected therewith and with the leversand means for raising the piston; substantially as set forth.

2. The combination of the standard, the parallel levers having fulcrumstherein, the seat frame, the bar 39 pivoted to each of said levers andextending backwardly and over the point of application of power to saidlevers and journaled in said frame, and mechanism for moving the leversabout the fill crums consisting of a piston having a rod pivotallyconnected therewith and with the levers and means for raising thepiston; substantially as set forth.

3. The combination of the standard, the parallel levers having fulcrumstherein, the seat frame, the bar 39 pivoted to each of said levers andextending backwardly and over the point of application of power to saidlevers and journaled in said frame, and mech anism for moving the leversabout the fulcrums consisting of a piston having a rod pivotallyconnected therewith and with the levers, means for raising the piston,and means adapted to automatically lower the same; substantially as setforth.

4:. In combination a seat frame, a rack fast on said. frame, anelevating bar 39 loosely connected to and supporting the frame,mechanism for raising the bar consisting of the parallel bars fulcrumedin a chair standard and the piston and piston rod, said rod beingpivotally connected both to the piston and to the levers, and a pawlhaving a lever extension pivoted to and movable with said elevating bar;whereby the chair seat can be raised and automatically lowered and alsotilted and locked in the tilted position at any desired elevation;substantially as set forth.

5. The standard having an open side and top and having its upper partenlarged or laterally entended, levers having fulcrums in saidextensions and extending through the open side of the standard, the seatsupported on said levers and means for raising and lowering the latter;substantially as set forth.

6. The rotatable chair standard provided with a lateral extension nearits upper part and a vertical slot on the side opposite the extension, aseat elevating piston, a reservoir containing the same and situatedadjacent to the standard wall below said extension, a centrally situatedclamping lever, and seat ele' vating levers fulcrurned in saidextension,

both the clamping and the elevating levers extending through said slot;substantially as set forth.

7. The standard having a closed bottom and circumferential walls adaptedto inclose seat-elevating devices and provided with a lateral extensionand with elevating levers fulcrumed in its extension and slotted at oneside for the passage of a standard-clamping handle 7 and of theelevating levers,the opentopped reservoir situated on said bottom at oneside of its center, the pump, and the main piston cylinder situated inthe reservoir, and a valve having an operating handle situated above thereservoir and extending through the inclosing wall of the standard;substantially as set forth.

8. In combination the seat frame, the back frame slotted in its bottomand rear and pivotally connected to said seat frame, the brace pivotedto the same frame and having at its outer end a pivoted screw andclamping nut, said screw being adapted to move in the rear slot of theframe when not clamped; substantially as set forth.

9. In combination the swinging back frame 56, provided with grooves, thesliding frame 66 fitting said grooves and itself provided with grooves,the bar 69 fitting the latter grooves, the rod situated in a passage inthe bar, and a friction pawl pivoted in the bar, and adapted to beoperated by the rod to lock the slide bar to the sliding frame, meansfor relatively moving the bar and rod, means for clamping the mainsliding frame to the back frame, and a head rest supported from the barand rod; substantially as set forth.

10. In combination the head rest, the lever having arms embracing a partof said rest, a second lever crossing the first and having a seat forsaid part, said levers having a common fulcrum, a second pair of lovershaving a common fulcrum, and overlapping the pair first named, a boltpassing loosely through the overlapping arms of the four levers andengaging the interior ones, and mechanism for forcing together the endsof the said second pair of levers which are opposite said bolt to clampthe head rest; substantially as set forth.

11. The foot rest roll frame having a curved groove in each end, and afoot rest or platform frame provided with lugs fitting said grooves theroll frame being provided with one or more rolls and adapted to he slidon the lugs to and from the chair seat to give various elevations of aroll; substantially as set forth.

12. Asupporting roll-frame havingacurved groove in each end and a footrest frame having lugs fitting said grooves provided with one or morerolls, the roll frame being adapted to be slid on the lugs toand fromthe chair seat to give various elevations of a roll, one of said groovescommunicating with notches on its under side to receive a lug wherebythe roll frame is secured in different positions; substantially as setforth.

In testimony whereof I have signed this specificationin the presence oftwo subscribing witnesses.

DEW ELL STUCK. Witnesses:

L. 1;. NASH, F. 13. HUTCHINSON.

